head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is variance, and it is a single point.

Optimization · Practiced Mastery
A top-down handheld GTA built around missions and a buy-low-sell-high drug economy.

Optimization · Practiced Mastery
A sprawling open-world crime epic with RPG-style character stats across a whole state.
Grand Theft Auto: Chinatown Wars leans Optimization (Practiced Mastery); Grand Theft Auto: San Andreas leans Optimization (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto: Chinatown Wars
Touch minigames and top-down driving need modest dexterity
Grand Theft Auto: San Andreas
Flying school and drive-bys need decent hands
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto: Chinatown Wars
No adaptive opponents anywhere
Grand Theft Auto: San Andreas
Gang AI is scripted, never adaptive
Grand Theft Auto: Chinatown Wars leans a little harder on variance, though the gap is small.
Grand Theft Auto: Chinatown Wars
Drug market prices fluctuate semi-randomly
Grand Theft Auto: San Andreas
Territory wars and traffic add light randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto: Chinatown Wars
The drug-trading economy is the real solvable game
Grand Theft Auto: San Andreas
Stats, gym, weapon skill, and routes reward systematic play
A matching score does not mean a matching test. Two games can both sit at 10 on execution and demand completely different things of you - which is why the reasoning above matters more than the number beside it.